无线传感器网络环境下基于事件 驱动应用的节能TDMA协议

媒质接入控制是无线传感器网络设计的关键问题之一.由于媒质接入控制协议直接控制着节点无线通信模块的活动,而无线通信模块是传感器节点能量消耗的主要来源,因此MAC协议节能效率的好坏将严重影响网络的性能.基于TDMA的MAC协议具有固有的节能特性,即通过合理的TDMA调度避免传输碰撞以及减少节点空闲监听的时间.本文提出了ED-TDMA协议,一种面向事件驱动的传感器网络应用的TDMA协议.该协议根据当前源节点的数目动态地改变TDMA帧的长度,提高了信道利用率;同时采用位图方式的TDMA调度,极大地减少了TDMA调度的开销,节约了能量.此外,通过引入簇内覆盖的思想,使得簇内的活动节点数目为一常数,同时减少了工作节点的数目,从而延长网络的生命周期,并在一定程度上提高了系统的可伸缩性.实验结果显示,ED-TDMA协议更适用于网络负载较低、节点密度高的无线传感器网络.

An Energy-Efficient Event Driven TDMA Protocol for Wireless Sensor Network

One of the key problems for Wireless Sensor Network(WSN) is the design of Medium Access Control(MAC) protocol.MAC protocol controls the activity of wireless communication module of sensor nodes,which is the major consumer of sensor energy.The energy efficiency of MAC protocol makes a strong impact on the network performance.TDMA-based MAC protocol is inherently collision free,and can rule out idle listening since nodes know when to transmit.In this paper,we present ED-TDMA,an event driven TDMA protocol for wireless sensor network.ED-TDMA improves channel utility by changing the length of TDMA frame according to the number of source nodes,while saving energy with bitmap-assisted TDMA schedule.In addition,ED-TDMA employs intra-cluster coverage to prolong network lifetime and to improve system scalability.Simulation results show that ED-TDMA performs better for wireless sensor network with high-density deployment and low traffic.